Field
The described technology relates generally to a mask and a mask assembly. More particularly, the described technology relates generally to a mask used for depositing an organic layer and a mask assembly.
Description of the Related Art
Generally, as a representative example of a flat panel display, there are an organic light emitting display, a liquid crystal display, a plasma display panel, etc.
Among them, in order to manufacture the organic light emitting display, an electrode having specific patterns, an organic emission layer, etc. should be formed. The method for forming the electrode and the organic emission layer, etc. can be applied to a deposition method using a mask assembly.
More specifically, the organic light emitting display includes pixels that are a basic unit displaying images on a substrate and arrayed in a matrix form, and an organic light emitting diode that has an anode, a first electrode and a cathode, and a second electrode sequentially formed, with organic emission layers each emitting light such as red, green, blue, or white, for each pixel therebetween. Organic materials forming the organic emission layer are very vulnerable to moisture and oxygen, etc., such that they should be thoroughly isolated from moisture during a process of forming the organic emission layer and after forming the organic emission layer. Therefore, it is difficult to perform patterning using a general photolithography process. Consequently, the organic emission layer is formed using a mask in which pattern openings for penetrating deposition materials only through a portion corresponding to each pattern is formed.
Recently, a mask assembly including a frame including an opening and a plurality of masks in a band shape of which both ends are fixed to the frame, corresponding to the opening, has been used.
The mask assembly in the related art is fixed to the frame by applying tensile force to the mask, such that the shape of the pattern openings formed in the mask due to the tensile force applied to the mask may be deformed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.